Chennai Metro Tunnel Between Royapettah and Dr. Radhakrishnan Salai Nears Completion

This month, the Chennai Metro Rail is going to achieve a significant milestone in its Phase II expansion: the completion of the tunnel from Royapettah to Dr. Radhakrishnan Salai. This will put an end to a year’s worth of boring and ease the progress of Corridor 3 in the entire 118.9 km project.

Currently, Corridor 3 spans 45.8 km, running from Madhavaram to SIPCOT via Royapettah and Mylapore. The corridor is one of the three major corridors in the development phase. The majority of the line from Madhavaram to Taramani lies below ground level, with tunnel boring machines (TBMs) expected to cut through many subsoils of the city. Each segment is drilled precisely with respect to station locations, soil conditions, and proximity to key structures.

The TBM deployed for this stretch, named ‘Bhavani’ after the river, began operations in July 2023 at Royapettah station. It has since covered 966 metres towards Dr. Radhakrishnan Salai and is now close to completing the alignment. Chennai Metro Rail Limited (CMRL) officials confirmed that the breakthrough will be achieved by the end of this month.

Despite earlier concerns about weathered rock and clay, tunnelling was smoother than anticipated. “This was a fairly easy stretch with sand and silt making up most of the soil profile. The TBM faced no major hiccups. We were cautious while drilling under the Government Royapettah Hospital, but the operation was successful,” an official said.

Another TBM, christened Adyar, is expected to complete tunneling in this area by October, thus furthering work on the corridor.

The Royapettah station, which is ideally situated adjacent to the YMCA, Government Royapettah Hospital, and a large shopping mall, is complemented by the station located on Dr. Radhakrishnan Salai, which is advantageous for hotels and offices. The full operation of the underground link is anticipated to greatly improve travel for thousands of daily commuters by providing easy access across the north and south of Chennai.

The new stretch that connects greatly to travel time with reduced road congestion for Corridor 3, which connects heavy-density residential, commercial, and business hubs, would surely position the Chennai Metro as the backbone of urban mobility in the city.